Reversible turbine



J. LISTON REVERSIBLE TURBINE sept. 19, 1961 4 Sheets-Sheet 1 Filed oct. 14, 1957 Sept. 191961 J. LlsToN REVERSIBLE TURBINE 4 Sheets-Sheet 2 Filed Oct. 14, 1957 llllllll m J s mw V, T E ms N E TH m f. f Nma -f M mw. N.

J. LISTON REVERSIBLE TURBINE Sept. 19, 1961 4 Sheets-Sheet 5 Filed Oct. 14, 1957 RN., mm Es W 1/ H P E J ORA/E75.

Sept. 19, 1961 Filed Oct. 14, 1957 J. LlSToN REVERSIBLE TURBINE 4 Sheets-Sheet 4 INVENTOR. JasfP/M /5 70N,

vllllliil'l 3,000,611v REVERSIBLE TURB'INE JosephListon, 900 Robinson St, WestLafayette, Ind. Filed Oct. 14, 1957, Ser. No. 690,037 10 Claims. (Cl. 253-51) This invention relates to gas turbines and more especially to reversible turbinesl and control means therefor.

In carrying out the invention in its preferred form, I employ a turbine of the radial-flow type. The turbinehousing has an inlet opening receivinggas from a supply conduit, and associated with such inlet openings are means by which the entering gas can be controlled with respect both to its rate ofy liow and to thetangential direction in which it discharges against the blades of the turbine rotor. Such flow-controlling means is designed to minimize resistance to movement of the gas in order to eliminate as far as possible energy losses which would result from abrupt changes in the direction or crosssectional area of the gas passage. Means may be provided for jointly regulating both the aforesaid flow-controlling means and the source for the gas used by the turbine.

In the accompanying drawings, which illustrate the invention:

FIG. 1 is a fragmental isometric view of a turbine with portions ofthe housing broken away;

FIG. 2 is a fragmental cross-section of the turbine shown in FIG. 1;

FIG. 3 is an elevational View, partially broken away, showing a modified form of how-controlling means;

FIG. 4 is an elevational View showing operating mechanism for the device of FIG. 3;

FIG. 5 is an elevation showing still another form of flow-controlling means and an operating mechanism therefor;

FIG. 6 is an isometric view illustrating a different form of operating mechanism for the How-controlling means of FIG. 5 and FIG. 7 is a diagrammatic view showing a development of the cam employed in the device of FIG. 6i.

The turbine shown in FIGS. l and 2 comprises a rotor 10 having radial blades 11V and mounted for rotation within an enclosing housing 12. The housing 12 has a radiallyprojectinginlet portion 13 having outwardly converging side walls 14 andterminating in an inlet opening 15 adapted to receive flowing gases from `any appropriate source (not shown). The base of the inlet portion 13 has a substantial extent circumferentially ofthe housing 12, and within it is mounted means for regulatingfth'e gas flow to control operation of the turbine.

The flow-regulating means shown in FIGS. 1 and 2 comprises a V-shaped controller having a pair of similar wings and 21 disposed at an obtuse angle. The wings 20 and 21 are rigid with each other and with a stem 22 which is located at the junctionl ofl the wings and projects perpendicularly'to the common plane of the wings, The stem-22 is rotatably mounted in the housing-portion 13, and one end ofY it extends outwardly through and beyond a wall of the portion 13 to be accessible for adjustment ofv the controller about the axis of the stem.

Shrouds 24 and 25 are respectively associated with the wings 2li and 21. Each-of such shrouds is conveniently formed of sheet metalv bent into a U-shape in cross-section to provide side walls and an intermediate wall. Each shroud is disposed' with itsA intermediate wall adjacent'a sidewall 14 of the housing portion 13 and with its side walls, which are generally triangular in shape, extending inwardly on opposite sides of the associated controller wing Ztl4 or 21. At their adjacent ends, the corresponding side walls of thetwo shrouds overlap, and

both pairs ofside walls are providedA with` openings which receive the stem 22. The shrouds are freely'movable about the axis ofv the. stem 22 and are respectively urged toward the turbine-axis, as by springs 26 and 27, `and toward engagement with stop-pins 28l and 29v so located as to prevent either shroudor its associatedcontroller-wing 20 or 21 from coming into contact with the' rotor 10.

In FIGS. l and 2, the controller is disposed to provide` for full-throttle operation of the turbine in the clockwise.

direction. The stem 22 has been rotated to its clockwise limit to bring the wing 20 into engagement with the pin 28, and the spring 26 has forced the shroud 24 also into engagement with such pin. The other controller wing 21 has engaged the intermediate wall of the shroud 25 and has forced such shroud away from its stop-pin 29. In this condition, the wing 20 and shroud 24 define a nozzlelike duct open at its upper end to receive gas entering through opening 15. Such duct is also open at its lower or discharge end, as the shroud is so constructed that when both it and the wing 20 are in engagement with the pin 28, the end of the wing 20 will be spaced from the intermediate wall of the shroud. At the opposite side of the deector, the corresponding nozzle-like duct is closed, as the spring 27 holds the intermediate wall of the shroud 25 in contact with the end of the wing 21. In consequence, all the gas entering the opening 15 will be discharged tangentially in a clockwise ydirection against the rotor-blades 11.

For part-throttle operation in a clockwise direction, the stem 22 and controller 20-21 are rotated in a counterclockwise direction, thus moving the end of the wing 20 toward the intermediate wall of the shroud 24, which remains stationary against the pin 28 under the influence of spring 26. At the same time, the spring 27 acts on the shroud 25 to maintain engagement of its intermediate wall with the end of the wing 21 and prevent discharge of gas in a counter-clockwise direction from the shroud 25. Continued counter-clockwise rotation of the controller results in eventual complete closing of the passage through the-shroud 24 and, after the shroud 25 engages the pin 29, progressive opening of the passage through the shroud 25.

Depending on whether or not it is deemed undesirable to` load the gas-source by full throttling of its output, the mechanism of FIGS. l and 2 can be constructed in either ofV two different forms; If it is not deemed necessary to avoid full'throttling, theshroud wallsr can be so shaped and the stop pins 28 and 29 so located that either controller wing, in moving away from fully open position, will `attain closed position against the intermediate wall of its-associated shroud before the other shroud engages itsstop pin. Since engagement of either shroud with its stop pin is necessary to opening of the passage-through the, shroud; bothpassages wouldbe-closed, and the gassource fully throttled, when the controller was in midposition. Alternatively, the stop pins 28 and 29 can be so-locatedas to engage a shroud before the passage throughtheother shroud has been fully closed. In such an arrangement, the Vpassages through both shrouds would be partially open when the controller was in or adjacent its'rnid-postion and gas would be discharged in both directions against the turbine blades, thus making it possible to reduce the application ofthe net driving eiort, even to zero, without completely throttling the gas-source.

Preferably, the walls 14- of the housing-portion 13 are oIset-.outwardly above the-tips of the wings 20, 21 and shrouds 24; 25, leaving shoulders 31V closely adjacent the pathsr of movement of, such wing and shroud tips. Sucholsetting provides a space for the-reception of each wing-tip; andv shroudwhen theI latter.- moves away from engagement with its associated stop pin 2&0112292' This Patented Sept. 19,Y 1961 A arrangement makes it possible for the intermediate wall of a shroud in engagement with its stop pin to lie substantially flush with that part of the housing wall below the shoulder, thus providing for the entering gas a substantially continuous now-guiding surface free from obstruction which would impede gas-flow.

It is possible to eliminate the shrouds 24 and 25 and to control the direction and rate of flow of the entering gas by cooperating of the tips of the wings 20, 21 with the shoulders 31. However, in such an arrangement, when either wing-tip moved inwardly beyond its associated shoulder 31 to open a passage for flow of 'gas to the rotor, the shoulder would provide a partial obstruction to gas-How and cause a loss of energy.

The embodiment of the invention illustrated in FIGS. 3 and 4 provides an improved streamlining of the inlet passage, especially at full-throttle. In it, the inlet portion of the housing comprises opposed, front and rear walls 35 and 36 and side walls 37 and 38 which diverge toward the turbine-housing 12. The side walls 37 and 38 are of elastic stock, and have a width substantially equal to the spacing of the front and rear walls so that they can enter therebetween. Extending between the front and rear walls 35 and 36 is a V-shaped flow director having wings 39 and 40 which diverge toward the housing 12, or in the direction of gas flow. Adjacent the ends of the wings 39 and 40, shafts 41 and 42 are supported from the front and rear walls 35 and 36, such shafts projecting through the front or rear walls for connection to any suitable control mechanism. Vanes 43 and 44 located between the front and rear walls are secured to the shaft 41 and 42 respectively to be rotated by the shafts in controlling the direction and rate of iiow of gas entering the housing 12.

Each of the side walls 37 and 38 is secured at its lower end to the housing 12 and extends upwardly therefrom well beyond the flow-director 39-40 into overlapping relation with rigid side-wall portions 45 and 46. Springs 47 connected to the upper ends of the side walls urge them upwardly and hold them against the outer faces of the rigid wal-l portions 45 and 46. By this arrangement, either side wall can be deiiected inwardly against the How-director to cooperate with the opposite wing thereof in forming a smoothly curved, essentially continuous surface confining lgas flowing to the housing along the other side wall. The side wall 3S is shown so deflected in dotted llines in FIG. 4.

Means for deflecting the side walls 4inwardly may take any appropriate form. That shown in the drawings comprises a pair of shafts 51 and 52 which lie outwardly of the side walls and are rotatably mounted in ears 53 provided on the front and rear walls 35 and 36. Such shafts carry arms 54 and 55 on the outer ends of which are mounted rollers 56 each adapted to engage the `adjacent side wall and deect it toward, and even into, engagement with the director 39-40 as the arm swings inwardly.

Any appropriate means may be provided for controlling the position of the Vanes 43, 44 and the arms `54, 55, either jointly or independently. The precise form of such means will depend to an extent on whether or not it is desired to be able to position both Vanes simultaneously in open position (as shown in full lines in FIG. 4) for the purpose of unloading the source of gas supplied to the turbine. The form of controlling means shown in FIG. 4, which is not capable of positioning both Vanes simultaneously in full open position, comprises a rotatable cam plate v69 having cam grooves or slots which receive pins 61 mounted on the ends of arms 63 and 64 secured respectively to the vane-supporting shafts 41 and 42. The pin-receiving slots of the cam plate 60 respectively include spiral portions 65 and 66 and concentric portions or lands 67 and 68. Each concentric slot-portion joins its associated spiral portion at the inner end thereof and lies diametrically opposite the spiral portion of the other slot.

A pin 70 mounted in an eccentric position on the cam plate 60 is connected to the inner ends of two links 71 and 72 the outer ends of which are connected to arms 73 and 74 secured respectively to the shafts 51 and 52.

In the condition illustrated in FIG. 4, the cam plate 60 is set for full-throttle operating of the turbine in the clockwise direction. The pin 61 on the arm 63 lies at the outer end of the spiral slot-portion 65 to hold the vane 43 in fully-open position, while the pin 61 on arm 64 lies at the end of the concentric slot portion 68 to maintain the vane 44 in closed position. The pin 70, at the limit of its motion in a clockwise direction, holds the arm 54,in inoperative position and the arm 55 in such position that the side wall 38 is deflected inwardly against the wing 40 of the flow-director. In this condition, a smooth-walled, streamlined passage is provided for the entering gas, which discharges past the open vane 43 to impinge upon the blades 11 and drive the rotor 10 in the clockwise direction.

On movement of the cam plate in a counterclockwise direction from the position of FIG. 4, the spiral slotportion 65 will initially cause the vane 43 to move toward closed position, which will be attained when the `inner end of the slot-portion reaches the pin. During such initial movement of the cam plate, the pin 61 on arm 64 will occupy the concentric slot-portion 68, and the vane 44 will therefore remain closed. As counterclockwise movement of the cam plate continues, the concentric slot-portion 67 will move into association with the pin 61 on arm 63, and the spiral slot-portion 66 will cause the vane 44 to move toward open position. Thus the Vanes 43 and 44 may be jointly adjusted to provide for full-throttle or part-throttle operation of the turbine in either direction.

During movement of the cam plate 60 in the counterclockwise direction as above described, the pin 70, acting through the links 71, 72 and arms 73, 74 will swing the arm 54 inwardly to force the side wall 37 against the wing 39 and the arm 55 outwardly to permit the side wall 38 to assume its normal position.

The structure shown in FIG. 5 embodies the Vanes 43 and 44 and Vane-controlling mechanism of FIG. 4, but employs a different arrangement for streamlining the gas flow. In that arrangement, the side walls of the inlet portion of the housing comprise rigid portions 81 and 82, which converge upwardly to a point adjacent the apex of the flow-director 39-40, and movable sections 83 and 84, each pivotally mounted at its upper end and swingable between a iirst position in which it lies flush with its associated rigid portion 81 or 82 and a second position in which it lies ush with the opposite wing 40 or 39 of the flow-director. In FIG. 5, section 83 is shown in its first position and section 84 in its second position.

Control of the swinging sections 83, 84 is effected through a member 85 pivotally mounted between the pivots 83', 84 about which the sections 83 and 84 respectively swing. The member 85 has a pair of oppositely projecting `arms operatively connected to arms 86 and 87 respectively rigid with -the sections 81, 82 and projecting outwardly from the pivots 83', 84. As will be clear from FIG. 5, the arrangement is such that by rocking the member 85, one of the sections 83 and 84 can be moved from its iirst position to its second position while the other section is moved from its second position to its first position. For the purpose of so rocking the member 85 it includes a third arm which extends downwardly into a position overlying the cam plate 60, where it is provided with a slot having two symmetrical portions 88 and 89 which receive a pin 90. eccentrically mounted on such cam plate. Each of the slot-portions 88 and 89 is in the form of a circular arc, but the two arcs have different centers which are so spaced that when the member 85 is at one limit of its swinging movement one slot-portion will be concentric with the cam plate 60 while the other t will be concentric with the cam plate when the member 85 is at the opposite limit of its swinging movement.

In the condition shown in FIG. 5, the cam plate 60 occupies the same position as in FIG. 4, the vane 43 is in full-open position, and the vane 44 rin fully closed position. The member 85 is in the counterclockwise limit of its swinging movement, to hold the section 83 in its first position and the section 84 in its second position, and the slot-portion 88, which is occupied by the pin 90, is concentric with the plate 60. Because of the latter condition, the cam plate 60 can be rotated oounterclockwise to move the vane 43 toward closed position whiie the member 85 and the sections 83 and 84 remain stationary until the pin 90 enters the other slot-portion 89. As such slot portion 89 is not concentric with the cam plate, continued movement of the cam plate will rock the member 85 in a clockwise direction causing it to move section 84 to its rst position and section 83 to its second position. Thus a smooth-walled passage for the entering gas is provided irrespective of which vane 43 or 44 is open and irrespective of whether it is fully or only partly open.

To expedite reversal in the positions of the sections 83, 84 when the cam plate 60 passes through the mid-point of its movement, the outer ends of the arms 86 and 87 may be interconnected by a helical tension spring 91, the effective axis of which will pass through the plane of the pivots 83 and 84 when the member 85 passes through the mid-point of its movement.

FIGS. 6 and 7 illustrate an alternative form of means for controlling the positions of the vanes 43, 44 and wallsections 83, 84. Here, the cam plate 60 is replaced by a cylinder cam 95 having three axially spaced, helical camgrooves 96, 97, and 98. The two end grooves 96 and 98 receive cam followers 96 and 98' carried respectively by the vane-controlling arms 64 and 63, while the middle groove 97 receives a cam follower 97 on the third arm of the member 85. l

A preferred form for the cam grooves 96, 97, and 98 is shown in FIG. 7, wherein the cam 95 is shown in development. As there shown, the grooves 96 and 98 at their mid-points have relatively short plane portions or dwells 96a and 98a so disposed axially that when occupied by the followers 96 and 98 both vanes 43 and 44 will be partially open. With the vanes in such positions gas entering the housing 12 will be substantially throttled and, since it discharges in both directions against the rotor, no substantial torque will be developed by the turbine. Movement of the cam 95 in one direction (downwardly in FIG. 7) from its mid-position will successively bring three additional portions 976b, 956e, and 96d of the groove 96 into association with the follower 96 and two portions 98e and 98]c of the groove 98 into successive association with the follower 98. Movement of the cam in the opposite direction from its mid-position will bring two portions 96e and 96]L of the groove 96 successively into associati-on with the follower 96 and three portions 98h, 98C, and 98d of the groove 98 into successive association with follower 98. Groove-portions 96b and 98h are rises having a sufficient axial extent to effect complete closing of the respectively associated vanes 44 and 43. Groove-portions 96C and 98C are dwells each of which, when occupied by its follower, holds the associated vane in fully closed position. Each of groove-portions 96d and 98d is inclined to effect progressive opening of the vane associated with the follower entering it. Groove portions 96e and 98e, which are respectively coextensive circumferential-ly with dwells 98e and 96C, are rises each of suicient axial extent to effect full opening movement of the associated vane. Groove portions 96]c and 981 are dwells respectively coextensive circumferentially with rises 98d and 96d, each serving when occupied by its follower to hold the associated vane in open position.

When the cam 95 is in the mid-position shown in the drawings, the cam follower 97 on the member 85 occupie's the mid-point of a rise 97a of the groove 97, and the wall-sections 83 *and 84 lie intermediate theirrespective first and second positions. The rise 97a desir-ably has 'a relatively steep pitch so as to bring one wall section quickly into its first position and the other quickly into its second position when the cam 95 is displaced from mid-position. The hand of the rise 97a is of course such as to bring the wall section 83 into its rst position and the section 84 into its second position when the cam 95 is rotated to open the vane 43 and close the vane 44. At its one end, the rise 97a joins 4a dwell 97b which extends circumferentially to the end of groove portion 96e and its other end joins a dwell 97C extending circumferentially to the end of groove portion 98C. At the ends of its dwells 97b and 97C, the groove 97 is shown as provided with rises 97d `and 97e, the purpose of which will become apparent below.

As will be clear, movement of the cam 95 from its central position in one direction-downwardly in FIG. 7 will close vane 44 and open vane 43, and at the same time, the member 85 will be rocked to bringk the section 83 into its first position and the section 84 into its second position. The movement `or the vane 44 and of the wall sections to their respective ultimate position-s will occur relatively quickly and will be completed before the vane 43 is fully opened. Continued movement of the cam in the assumed direction will progressively open the vane 43 until the condition shown in FIG. 5 is attained, the cam followers 96 and 97' meanwhile respectively occupying the dwells 96C and 97b. For counterclockwise rotation of the turbine, the cam 95 is moved in the opposite direction (upward in FIG. 7).

The groove-portions 96d, 97d, 981, 96gc and 98d are particularly useful where the cam 95 is controlled by a speed limiting governor and the gas source is of such a character that abrupt throttling of its output would be undesirable. Consider, for example, the situation exist- 'ing if the turbine, operating under full throttle, was suddenly relieved of load. The resultant tendency of the turbine to over-speed could be corrected by moving the cam to, or even through, its mid-position; but if such cam movement was effected abruptly, the consequent abrupt throttling of the inlet passage might tend to overload or produce erratic operation of the gas-source. The cam portions last referred to make it possible to reduce the speed of the turbine quickly without unduly loading the gas-source. For example, if with the cam-follower 96 occupying the groove-portion 96o, the follower 98' at or near the upper end of `the groove-portion 98e, and the turbine rotating clockwise, an abrupt speed reduction is desired, the cam may be moved to bringthe followers 96' and 98' into the groove-portions 96d and 98], re-

spectively, `and the cam-follower 97 intothe rise 97d.

Such operation will leave open the already fully-opened vane 43 to continue the clockwise introduction of the gas, but will open the previously closed vane 44 and section 84, thereby causing gas to be also introduced in a counterclockwise direction. VThe latter gas, by opposing rotation of the rotor, will reduce the speed while, at the same time, avoiding the imposition of undue load on the gas-source.

The cam 95 may be provided with additional cam surfaces for controlling auxiliary equipment, such as the gas-source. y

While I have described the various illustrated embodiments of my invention as providing Ialternatively for rotation of the turbine in either direction, it will be under- 7 simply varying the division of the iiowing gas between ghe two nozzle-like passages which the vanes in part de- Because the illustrated embodiments provide for complete reversibility of the turbine and for similar operation in opposite directions, the gas controlling elements are symmetrically arranged and the rotor blades 11 are radial. If the operational characteristics are not to be the same for opposite `directions of rotation, such symmetry will not be necessary and may even be undesirable.

It will be further understood that the specific embodiments of the invention illustrated and described above are set forth merely by way of examples, that other embodiments are possible, and that the scope of the invention is to be measured by the appended claims.

I claim as my invention:

1. A reversible turbine, comprising a housing, a Vrotor having generally radial blades rotatably mounted Within Vsaid housing, an inlet conduit having opposite side Walls ilaring toward said housing and joining it substantially tangentially, means including vanes pivotally mounted between said flaring Walls for controlling the ow of gas toward said rotor, each of said vanes extending in the general direction of gas flow from its axis of pivotal mounting to a point adjacent the periphery of said rotor and in part defining a nozzle-like passage progressively decreasing in area toward an outlet opening at the tip of the vane, each of said vanes being swingable about said .axis to vary the size of said outlet opening, and control means for adjusting the position of each vane about its axis, the pivotal axis of each vane being located suiciently far from the associated wall of the inlet conduit that the vane and wall, in all positions of vane adjustment, will always converge relatively to each other in the direction of gas flow.

2. A turbine as set forth in claim 1 with the addition that said control means includes a single control member openable to eifect joint adjustment of said vanes.

3. A turbine as set forth in claim 1 with the addition of a movable member cooperating with each vane in defining the nozzle-like passage.

4. A turbine as set forth in claim 1 with the addition that said vanes are rigid with each other and areV swingable about a common axis.

5. A turbine as set forth in claim 1 with the addition of a shroud associated with each vane, each shroud being pivotally mounted on the axis of its associated vane and being of U-shaped cross-section to provide a pair of opposed, spaced walls between which the vane swings and an intermediate wall toward and away from which the vane swings, means urging each shroud to swing about its axis in such a direction as to cause its intermediate wall to approach the vane, and stationary stop means for limiting swinging of each shroud under the influence of said urging means.

6. A turbine as set forth in claim 1 with the addition that said vanes are pivotally mounted on spaced axes, a How-divider having wings which extend in converging relationship from the pivoted ends of said vanes anteriorly with respect to the direction o-f gas ow, and adjustable means for controlling the division of flowing gas between opposite sides of said flow-divider.

7. A turbine as set forth in claim 6` with the addition of common means for adjusting said vanes and said division-controlling means.

8. A turbine as set fonth in claim 6 with the addition that said division-controlling means includes a pair of members extending anteiiorly of said inlet conduit from said flow-divider, the anterior ends of said members being located respectively adjacent the side walls of the inlet conduit, each of said members being movable between a first position in which it is spaced transversely of the inlet conduit from said flow divider and a second position in which it extends obliquely with its posterior portion lying in close proximity to said oW-divider.

9. A reversible turbine, comprising a housing, a rotor having generally radial blades rotatably mounted within said housing, an inlet conduit having opposite side Walls ilaring toward said housing and joining it substantially tangentially, a how-divider located centrally in said inlet conduit for directing flow toward said side walls, means located anteriorly of said flow-divider and adjustable to control the division of owing gas between opposite sides thereof, said means being capable of adjustment to direct substantially all the owing gas alternatively to either side of the How-divider, vanes pivotally mounted on transversely spaced parallel axes adjacent the posterior end of said flow-divider, each of said vanes extending generally in the direction of gas flow from its pivotal axis and being swingable thereabout to cooperate with the adjacent side Wall lof the inlet conduit in defining a nozzle-like passage of progressively decreasing area in the direction of gas liloW, and common means for adjusting said vanes and said division-controlling means.

10. A turbine as set forth in claim 9 with the addition that `said common means comprises an adjustable cam and cam-followers respectively connected to said vanes and division-controlling means, said cam being so constructed and arranged as to permit the cam to be moved to adjust the vanes while the adjustment of the divisioncontrolling means remains unchanged.

References Cited in the tile of this patent UNITED STATES PATENTS 919,289 Lake Apr. 20, 1909 1,061,858 lMcCulloch May 13, 1913 1,383,937 Guthrie July 5, 1921 2,421,445 Waller June 3, 1947 2,770,943 Beale Nov. 20, 1956 2,800,297 Ergenc July 23, 1957 

